App Registration v1.0

The screenshots on this page are in conjunction with the Excel API > Using VS Code with TypeScript SSO project.

link - learn.microsoft.com/en-gb/office/dev/add-ins/develop/register-sso-add-in-aad-v2 

Open a browser and login to your Azure Active Directory admin center with an administrator account.
On the left hand side, underneath Favorites, click on "Azure Active Directory".
At the top select (Add > App registration).

Registration & Authentication

Enter or choose the following items.

Name - "Excel-TypeScript-SSO" (this is the name of your VS Code project)
Supported account types - "Accounts in any organizational directory (Any Azure AD directory - Multitenant)"
Office Add-in Apps must be multi-tenant, they cannot be single tenant.
Redirect URI - leave this blank
Press Register.
Click on Authentication, under Manage.
Under Platform configurations, click on "Add a platform".

Select the Web platform from the list of options.
Enter or choose the following items.

Redirect URIs - https://localhost:8080/taskpane.html (your port number might be different)
Access tokens - Tick this box. Used for implicit flows
ID tokens - Tick this box. Used for implicit and hybrid flows
Press Configure.
Once the Web platform has been added, press Add URI to add another Redirect URI.
URI - https://localhost:8080/fallbackauthdialog.html
Press Save.

Certificates and Secrets

Click on Certificates & secrets, under Manage.
Select the Client Secrets tab, click on New client secret.

Enter or choose the following items.

Description - "anything"
Expires - "Recommended 6 months"
Press Add.
Once the new secret has been added to the list, make sure you copy the "Value".
You will need to add this value to your Visual Studio Code project.

Expose an API

Click on Expose an API, under Manage.
At the very top press the Set button.

Add "localhost:8080/" before the protocol and the unique ID of the application. Your ID will be different.

Press Save.
Under Scopes defined by this API, press "Add a scope".
Enter or choose the following items.

scope name - "access_as_user"
Who can consent - "Admins and users"
Admin consent display name - "Office can act as the user"
Admin consent description - "Enable Office to call the add-in's web APIs with the same rights as the current user."
User consent display name - "Office can act as you"
User consent description - "Enable Office to call the add-in's web APIs with the same rights that you have."
State - Enabled
Press Add scope.

Under Authorized client applications, press "Add a client application".
Enter or choose the following items.

Client Id - d3590ed6-52b3-4102-aeff-aad2292ab01c (for Microsoft Office)
Authorized scopes - Tick this box.
Press Add application.
Repeat this for another 4 Application GUIDS.
ea5a67f6-b6f3-4338-b240-c655ddc3cc8e (for Microsoft Office)
57fb890c-0dab-4253-a5e0-7188c88b2bb4 (for Office on the web)
08e18876-6177-487e-b8b5-cf950c1e598c (for Office on the web)
bc59ab01-8403-45c6-8796-ac3ef710b3e3 (for Outlook on the web)

API permissions

Add the permissions for accessing Microsoft Graph.
Click on API permissions, under Manage.
Under Configured permissions, click on "Add a permission".

On the Select an API screen, select Microsoft Graph.

Select Delegated permissions.

Select the following permissions from the list.

openid - Sign users in
profile - View user's basic profile
Press Add permissions.
Once the permissions have been added, press the "Grant admin consent for CompanyName" (only needed for MSAL).

Press Yes on the confirmation prompt.

Overview

Check the overview page to double check you have added everything.
Click on Overview, under Manage.
Under the Display name, make sure you copy the "Application (client) ID".
You will need to add this value to your Visual Studio Code project.

That is the registration part completed.

Windows Credentials with PowerShell

The last step is to create a new client secret and save it to your machine's local secret store.
For this step you will need your username.
Typing the word "System" into the Windows Search bar will display this information.
Typing the word "PowerShell" into the Windows Search bar will open this application.
Type the following lines one at a time and press Enter after each line.

$ssoAppName = "Excel-TypeScript-SSO" 
$user = "UserName" 
$secret = "SecretValue" 
[void][Windows.Security.Credentials.PasswordVault, Windows.Security.Credentials, ContentType = WindowsRuntime] 
$creds = New-Object Windows.Security.Credentials.PasswordCredential 
$creds.Resource = $ssoAppName 
$creds.UserName = $user 
$creds.Password = $secret 
$vault = New-Object Windows.Security.Credentials.PasswordVault 
$vault.add($creds) 

Typing the word "Credentials" into the Windows search bar will display the Credential Manager application.
Check that the Web Password has been added successfully.